How does one change the font for one set of lyrics?

[Connor Harris]

>not top-posting

I'm writing a choral piece with a French text for SATB divisi choir, two 
parts per staff. I'd like to have two sets of lyrics per part: one with 
the original text in French orthography, and one in IPA phonetic 
transcription underneath the "main" lyrics. Here's a fragment of the 
adapted Frescobaldi template that I'm using, defining the layout of the 
choir staves:

choirPart = \new ChoirStaff <<
  \new Staff = "ss" \with {
    instrumentName = "Soprano"
  } <<
    \new Voice = "soprano1" { \voiceOne \sopranoOne }
    \new Voice = "soprano2" { \voiceTwo \sopranoTwo }
  >>
  \new Lyrics \with {
    alignAboveContext = "ss"
    \override VerticalAxisGroup #'staff-affinity = #DOWN
  } \lyricsto "soprano1" \sopranoOneLyrics
  \new Lyrics \with {
    alignAboveContext = "ss"
    \override VerticalAxisGroup #'staff-affinity = #DOWN
  } \lyricsto "soprano1" \sopranoOneIPA
  \new Lyrics \lyricsto "soprano2" \sopranoTwoLyrics
  \new Lyrics \lyricsto "soprano2" \sopranoTwoIPA

  % and similarly for alto, tenor, bass
>>
where \sopranoOneLyrics et sim. refer to \lyricmode objects defined 
elsewhere.

The default serif font lacks many necessary IPA symbols and reverts to 
printing them in the default sans-serif font, which creates an ugly and 
hard-to-read mixture. To avoid this and better distinguish the French 
from the IPA, I'd like to print the IPA throughout in a sans-serif font, 
with the French text in the standard serif font. I don't know how to do 
this without enclosing every IPA syllable in its own \markup object and 
redefining the font there, which I would prefer to avoid; the most 
relevant pages that I could find with an Internet search gave methods of 
changing the global font for a document, or for changing the font for 
all sets of lyrics, neither of which is what I want. Many thanks for any 
help that you can provide!

Best,
Connor